The present invention relates to a sliding universal joint to be mounted at a bending portion of a bendable drive axle in an automobile, for example. More particularly, the invention is directed to an improvement in a joint including a cylindrical outer member connected to one transmitting shaft and having an inner periphery formed with plurality of transmitting grooves arranged circumferentially equally spaced from each other and extending axially, an inner member connected to another transmitting shaft and having a plurality of trunnions radially extending to project into the transmitting grooves, an inner roller slidably engaged with an outer periphery of each trunnion, a holder relatively oscillatably engaging with an outer periphery of each inner roller, and an outer roller rotatably engaging with an outer periphery of each holder and engaged with the respective transmitting groove.
This type of universal joint is known as disclosed in Japanese Patent Publication No. 57-13211.
In the conventional joint, when both transmitting shafts are bent relative to each other during transmission of torque, the outer roller is reciprocatingly rolled in the transmitting groove permitting inclination of the trunnion. The inclination of the trunnion follows the inclination of the outer roller, causing an increase in rolling resistance of the outer roller and thus, generating vibration.
The present invention has been achieved to solve the above problem, and it is an object of the present invention to provide a sliding universal joint in which inclination of the outer roller is prevented even when the trunnion is inclined and the outer roller is allowed to reciprocatingly roll in the transmitting groove with a proper rolling condition maintained, and which may be easily manufactured.
According to the present invention, there is provided in a sliding universal joint the improvement comprising a restriction plate formed independently of the holder and fixed to a side edge portion of the holder at an opening of the transmitting groove, and a rail portion provided on the outer member, the rail portion abutting against the restriction plate and restricting inclination of the holder.
When this arrangement, the restriction plate of the holder abuts against the rail portion of the outer member. Accordingly, even when the trunnion is inclined, the holder is suppressed from being inclined. As a result, the outer roller supported on the holder is prevented from being inclined, thereby allowing a smooth reciprocal rolling motion of the outer roller in the transmitting groove.
Further, as the restriction plate is manufactured independently of the holder, it is easily formed in a rectangular shape, for example, suitable for restriction of inclination of the holder.